The World Bank has published a report entitled, ‘A Primer on Energy Efficiency for Municipal Water and Wastewater Utilities’ through its Energy Sector Management Assistance Program (ESMAP).
Though this report focuses on infrastructure in developing nations, it can also be applied to the energy efficiency of many small and medium rural and urban U.S. water and wastewater systems.
According to an article by Bridget O’Grady, ESMAP has four main points to support its stance on energy efficiency in relation to water:
- Since energy represents the largest controllable operational expenditure of most water and wastewater utilities (WWUs), and many energy-efficiency (EE) measures have a payback period of less than five years, investing in EE supports quicker and greater expansion of clean water access for the poor by making the system cheaper to operate.
- Improving energy efficiency is at the core of measures to reduce operational cost at WWUs.
- Electricity costs are usually between 5 to 30 percent of total operating costs among water and wastewater utilities worldwide.
- Electricity is a critical input for delivering municipal water and wastewater services.
The aforementioned article also discusses data on groundwater versus surface water usage. Surface water-based supply systems’ energy use is dominated by pumping for distribution of treated water (70 to 80 percent of overall electricity consumption), leaving the remaining small percentage to raw water pumping and the treatment process. Ground water-based supply systems are typically more energy consuming than surface water because of higher pumping needs for water extraction, yet they require less treatment, since the main treatment is chlorination for raw water. To read the full article, click here. To view or download the complete World Bank ESMAP Primer, click here.